This is a note to let you know that I've just added the patch titled

x86/dumpstack: Indicate in Oops whether PTI is configured and enabled

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: x86-dumpstack-indicate-in-oops-whether-pti-is-configured-and-enabled.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From 5f26d76c3fd67c48806415ef8b1116c97beff8ba Mon Sep 17 00:00:00 2001

From: Vlastimil Babka vbabka@suse.cz Date: Tue, 19 Dec 2017 22:33:46 +0100 Subject: x86/dumpstack: Indicate in Oops whether PTI is configured and enabled

From: Vlastimil Babka vbabka@suse.cz

commit 5f26d76c3fd67c48806415ef8b1116c97beff8ba upstream.

CONFIG_PAGE_TABLE_ISOLATION is relatively new and intrusive feature that may still have some corner cases which could take some time to manifest and be fixed. It would be useful to have Oops messages indicate whether it was enabled for building the kernel, and whether it was disabled during boot.

Example of fully enabled:

Oops: 0001 [#1] SMP PTI

Example of enabled during build, but disabled during boot:

Oops: 0001 [#1] SMP NOPTI

We can decide to remove this after the feature has been tested in the field long enough.

[ tglx: Made it use boot_cpu_has() as requested by Borislav ]

Signed-off-by: Vlastimil Babka vbabka@suse.cz Signed-off-by: Thomas Gleixner tglx@linutronix.de Reviewed-by: Eduardo Valentin eduval@amazon.com Acked-by: Dave Hansen dave.hansen@intel.com Cc: Andy Lutomirski luto@kernel.org Cc: Andy Lutomirsky luto@kernel.org Cc: Boris Ostrovsky boris.ostrovsky@oracle.com Cc: Borislav Petkov bp@alien8.de Cc: Brian Gerst brgerst@gmail.com Cc: Dave Hansen dave.hansen@linux.intel.com Cc: David Laight David.Laight@aculab.com Cc: Denys Vlasenko dvlasenk@redhat.com Cc: Greg KH gregkh@linuxfoundation.org Cc: H. Peter Anvin hpa@zytor.com Cc: Josh Poimboeuf jpoimboe@redhat.com Cc: Juergen Gross jgross@suse.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Will Deacon will.deacon@arm.com Cc: aliguori@amazon.com Cc: bpetkov@suse.de Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: jkosina@suse.cz Cc: keescook@google.com Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- arch/x86/kernel/dumpstack.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -297,11 +297,13 @@ int __die(const char *str, struct pt_reg unsigned long sp; #endif printk(KERN_DEFAULT - "%s: %04lx [#%d]%s%s%s%s\n", str, err & 0xffff, ++die_counter, + "%s: %04lx [#%d]%s%s%s%s%s\n", str, err & 0xffff, ++die_counter, IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "", IS_ENABLED(CONFIG_SMP) ? " SMP" : "", debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "", - IS_ENABLED(CONFIG_KASAN) ? " KASAN" : ""); + IS_ENABLED(CONFIG_KASAN) ? " KASAN" : "", + IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION) ? + (boot_cpu_has(X86_FEATURE_PTI) ? " PTI" : " NOPTI") : "");

if (notify_die(DIE_OOPS, str, regs, err, current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP)

Patches currently in stable-queue which might be from vbabka@suse.cz are

queue-4.14/x86-dumpstack-indicate-in-oops-whether-pti-is-configured-and-enabled.patch